Hi Jared, Theoretically, MAP is better. But 1. Nobody has implemented it for the router. The code for the CGNAT engine gives the same cost/performance. No promised advantage from potentially stateless protocol.
2.MAP needs much bigger address space (not everybody has) because: a) powered-off subscribers consume their blocks anyway b) it is not possible to add "on the fly" additional 64 ports to the particular subscriber that abuse some Apple application (and go to 1k ports consumption) that may drive far above any reasonable limit of ports per subs. Design should block a big enough number of UDP/TCP ports for every subs (even most silent/conservative). Ed/ -----Original Message----- From: NANOG [mailto:[email protected]] On Behalf Of Jared Brown Sent: Friday, March 25, 2022 4:49 PM To: [email protected] Subject: MAP-T (was: Re: V6 still not supported) Most IPv6 transition mechanisms involve some form of (CG)NAT. After watching a NANOG presentation on MAP-T, I have a question regarding this. Why isn't MAP-T more prevalent, given that it is (almost) stateless on the provider side? Is it CPE support, the headache of moving state to the CPE, vendor support, or something else? NANOG 2017 Mapping of Address and Port using Translation MAP T: Deployment at Charter Communications https://www.youtube.com/watch?v=ZmfYHCpfr_w - Jared
